Using synthetic acid compositions as alternatives to conventional acids in the oil and gas industry

ABSTRACT

A synthetic acid composition for use in oil industry activities is disclosed. The composition comprises urea and hydrogen chloride in a molar ratio of not less than 0.1:1; a metal iodide or iodate; an alcohol or derivative thereof. Optionally, the composition may include formic acid or a derivative thereof propylene glycol or a derivative thereof, ethylene glycol glycerol or a mixture thereof; cinnamaldehyde or a derivative thereof; and a phosphonic acid derivative.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. 371 andclaims the benefit of PCT Application No. PCT/CA2015/000346 having aninternational filing date of 28 May 2015, which designated the UnitedStates, which PCT application claimed the benefit of Canadian PatentApplication No. 2,852,705 filed 30 May 2014, and Canadian PatentApplication No. 2,866,688 filed 2 Oct. 2014, the disclosure of each ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to compositions for use in performing variousapplications in the oil & gas industry, more specifically to syntheticacid compositions as alternatives to conventional acids.

BACKGROUND OF THE INVENTION

In the oil & gas industry, stimulation with an acid is performed on awell to increase or restore production. In some instances, a wellinitially exhibits low permeability, and stimulation is employed tocommence production from the reservoir. In other instances, stimulationis used to further encourage permeability and flow from an alreadyexisting well that has become under-productive.

Acidizing is a type of stimulation treatment which can be performedabove or below the reservoir fracture pressure in an effort to restoreor increase the natural permeability of the reservoir rock. Acidizing isachieved by pumping acid into the well to dissolve typically limestone,dolomite and calcite cement between the sediment grains of the reservoirrocks.

There are three major types of acid applications; matrix acidizing,fracture acidizing, and breakdown acidizing (pumped prior to afracturing pad or cement operation in order to assist with formationbreakdown (reduce fracture pressures, increased feed rates), as well asclean up left over cement in the well bore or perforations. A matrixacid treatment is performed when acid is pumped into the well and intothe pores of the reservoir formation below the fracture pressure. Inthis form of acidization, the acids dissolve the sediments and mudsolids that are inhibiting the permeability of the rock, enlarging thenatural pores of the reservoir (wormholing) and stimulating flow ofhydrocarbons. While matrix acidizing is done at a low enough pressure tokeep from fracturing the reservoir rock, fracture acidizing involvespumping highly pressurized acid into the well, physically fracturing thereservoir rock and etching the permeability inhibitive sediments. Thistype of acid treatment forms channels or fractures through which thehydrocarbons can flow, in addition to forming a series of wormholes.

There are many different mineral and organic acids used to perform anacid treatment on wells. The most common type of acid employed on wellsto stimulate production is hydrochloric acid (HCl), which is useful instimulating carbonate reservoirs.

Some of the major challenges faced in the oil & gas industry from usinghydrochloric acid include the following: extremely high levels ofcorrosion (which is countered by the addition of ‘filming’ typecorrosion inhibitors that are typically themselves toxic and harmful tohumans, the environment and equipment) reactions between acids andvarious types of metals can vary greatly but softer metals, such asaluminum and magnesium, are very susceptible to major effects causingimmediate damage. Hydrochloric acid produces Hydrogen chloride gas whichis toxic (potentially fatal) and corrosive to skin, eyes and metals. Atlevels above 50 ppm (parts per million) it can be immediately Dangerousto Life and Health (IDHL). At levels from 1300-2000 ppm death can occurin 2-3 minutes.

The inherent environmental effects (organic sterility, poisoning ofwildlife etc.) of acids in the event of an unintended or accidentalrelease on surface or downhole into water aquifers or other sources ofwater are devastating which can cause significant pH reduction of suchand can substantially increase the toxicity and could potentially causea mass culling of aquatic species and potential poisoning of humans orlivestock and wildlife exposed to/or drinking the water. An unintendedrelease at surface can also cause a hydrogen chloride gas cloud to bereleased, potentially endangering human and animal health. This is acommon event at large storage sites when tanks split or leak. Typicallyif near the public, large areas need to be evacuated post event. Becauseof its acidic nature, hydrogen chloride gas is also corrosive,particularly in the presence of moisture.

The inability for acids and blends of such to biodegrade naturallyresults in expensive cleanup-reclamation costs for the operator shouldan unintended release occur. Moreover, the toxic fumes or vapoursproduced by mineral & organic acids are harmful to humans/animals andare highly corrosive and/or potentially explosive. Transportation andstorage requirements for acids are restrictive and taxing in such thatyou must haul the products in acid approved tankers or intermediate bulkcontainers (IBC) that are rated to handle such corrosive products. Aswell, the dangers surrounding exposure by personnel handling theblending of such corrosive/dangerous products limits theiruse/implementation.

Another concern is the potential for exposure incidents on locations dueto high corrosion levels of acids causing storage container failuresand/or deployment equipment failures i.e. coiled tubing or treatmentiron failures caused by high corrosion rates (pitting, cracks, pinholesand major failures). Other concerns include: downhole equipment failuresfrom corrosion causing the operator to have to execute a work-over andreplace down hole pumps, tubing, cables, packers etc.; inconsistentstrength or quality level of mineral & organic acids; potential supplyissues based on industrial output levels; high levels of corrosion onsurface pumping equipment resulting in expensive repair and maintenancelevels for operators and service companies; the requirement ofspecialized equipment that is purpose built to pump acids greatlyincreasing the capital expenditures of operators and service companies;and the inability to source a finished product locally or very near itsend use; transportation and onsite storage difficulties.

Typically, acids are produced in industrial areas of countries locatedfar from oil & gas applications, up to 10 additives can be required tocontrol various aspects of the acids properties adding to complicationsin the handling and shipping logistics. Having an alternative thatrequires minimal additives is very advantageous.

Extremely high corrosion and reaction rates with temperature increasescan cause conventional acids to “spend/react or become neutral” prior toachieving its desired effect such as penetrating an oil or gas formationto increase the wormhole “pathway” effectively to allow the petroleumproduct to flow freely to the surface. As an example, hydrochloric acidor a “mud acid” can be utilized in an attempt to free stuck drill pipein some situations. Prior to getting to the required depth to dissolvethe formation that has caused the pipe/tubing to become stuck, manyacids spend or neutralize due to increased bottom hole temperatures andincreased reaction rate, so it is advantageous to have an alternativethat spends or reacts more methodically allowing the slough to betreated with a solution that is still active, allowing the pipe/tubingto be pulled free.

When used to treat scaling issues on surface due to water contamination,conventional acids are exposed to human and mechanical devices as wellas expensive pumping equipment causing increased risk for the operatorand corrosion effects that damage equipment and create hazardous fumes.When mixed with bases or higher pH fluids, acids will create a highamount of thermal energy (exothermic reaction) causing potential safetyconcerns and equipment damage, acids typically need to be blended withfresh water (due to their intolerance of highly saline water, causingpotential precipitation of minerals) to the desired concentrationrequiring companies to pre-blend off-site as opposed to blending on-sitewith field/produced water thereby increasing costs associated withtransportation.

Conventional mineral acids used in a pH control situation can causerapid degradation of certain polymers/additives requiring increasedloadings or chemicals to be added to counter these negative effects.Many offshore areas of operations have very strict, regulatory rulesregarding the transportation/handling and deployment of acids causingincreased liability and costs for the operator. When using an acid topickle tubing or pipe, very careful attention must be paid to theprocess due to high levels of corrosion, as temperatures increase, thetypical additives used to control corrosion levels in acid systems beginto degrade very quickly (due to the inhibitors “plating out” on thesteel) causing the acids to become very corrosive and resulting indamage to downhole equipment/tubulars. Conventional acids are also verydestructive to most elastomers found in the oil & gas industry such asthose found in blow out preventers (BOP's)/downholetools/packers/submersible pumps/seals etc. Having to deal with spentacid during the back flush process is also very expensive as these acidstypically are still at a low pH and remain toxic. It is advantageous tohave an acid blend that can be exported to production facilities throughpipelines that once spent or applied, is commonly close to a neutral pHgreatly reducing disposal costs/fees.

Acids perform many actions in the oil & gas industry and are considerednecessary to achieve the desired production of various petroleum wells,maintain their respective systems and aid in certain functions (i.e.freeing stuck pipe). The associated dangers that come with using acidsare expansive and tasking to mitigate through controls whether they arechemically or mechanically engineered

Eliminating or even simply reducing the negative effects of acids whilemaintaining their usefulness is a struggle for the industry. As thepublic demand for the use of cleaner/safer/greener products increases,companies are looking for alternatives that perform the requiredfunction without all or most of the drawbacks associated with the use ofconventional acids.

U.S. Pat. No. 4,402,852 discloses compositions containing 5 to 75% ofurea, 5 to 85% of sulfuric acid and from 5 to 75% of water. Thesecompositions are said to have reduced corrosiveness to carbon steels.

U.S. Pat. No. 6,147,042 discloses compositions comprising apolyphosphoric acid-urea condensate or polymer which results from thereaction of orthophosphoric acid and urea used in the removal of etchingresidue containing organometal residues.

U.S. Pat. No. 7,938,912 discloses compositions containing hydrochloricacid, urea, a complex substituted keto-amine-hydrochloride, an alcohol,an ethoxylate and a ketone for use to clean surfaces having cementitiouscompositions. U.S. Pat. Nos. 8,430,971 and 8,580,047 disclose and claimcompositions containing specific amounts of hydrochloric acid (55% bywt); urea (42% by wt), a complex substituted keto-amine-hydrochloride(0.067% by wt); propargyl alcohol (0.067% by wt); an ethoxylatednonylphenyl (0.022% by wt); methyl vinyl ketone (0.022% by wt); acetone(0.0022% by wt); and acetophenone (0.0022% by wt) for use in specificoil industry applications, namely oil drilling and hydraulic fracturing.

U.S. Pat. No. 5,672,279 discloses a composition containing ureahydrochloride prepared by mixing urea and hydrochloric acid. Ureahydrochloride is used to remove scale in hot water boilers and otherindustrial equipment such as papermaking equipment. Scale is caused bythe presence of calcium carbonate which is poorly soluble in water andtends to accumulate on surfaces and affect equipment exposed to it.

U.S. Pat. No. 4,466,893 teaches gelled acid compositions comprising agelling agent selected from the group consisting of galactomannans suchas guar gum, gum karaya, gum tragacanth, gum ghatti, gum acacia, gumkonjak, shariz, locus, psyllium, tamarind, gum tara, carrageenan, gumkauri, modified guars such as hydroxypropyl guar, hydroxyethyl guar,carboxymethyl hydroxyethyl guar, carboxymethyl hydroxypropyl guar andalkoxylated amines. This patent teaches that presence of urea has amarked impact on the viscosity of the gelled acid and the gelled acidcompositions are used in fracking activities.

Several operations in the oil industry expose fluids to very hightemperatures (some upward of 200° C.), the compositions used in thesevarious operations need to withstand these high temperatures withoutlosing their overall effectiveness. These compositions must be capableof being used in operations over a wide range of temperatures while notaffecting the equipment with which it comes in contact.

Synthetic acid compositions are mostly applicable in the cleaningindustry. However, such compositions require the additional of a numberof various chemical compounds which are dangerous in their undilutedstates. The physical process to make such cleaning compositions involvesmultiple steps of mixing, blending and dilution. The present inventionproposes the removal of certain chemicals used which would rationalizethe process to make the compositions of the present invention andtherefore render the manufacturing process safer from a production pointof view. Moreover, it was discovered that the composition according tothe present invention exhibits stability for operations at elevatedtemperatures (above 65° C.) and therefore makes them useful in the oiland gas industry. The composition according to the present invention canideally be used in various oilfield operations, such as: spearheadbreakdown acid, acid fracturing operations, Injection-disposal welltreatments, scale removal treatments (surface and subsurface-,equipment, pipelines, facilities), formation filter cake removal, tubingpickling, matrix acid squeezes and soaks, cement squeeze breakdowns,fluid pH control, stuck pipe operations, and coiled tubing acid washes,soaks, squeezes.

The present invention provides a simpler/safer manufacturing process andabridged synthetic acid compositions for use in high temperature/volumeapplications such as various operations in the oilfield.

Consequently, there is still a need for compositions for use in the oilindustry which can be used over this range of applications which candecrease a number of the associated dangers/issues typically associatedwith conventional acid applications to the extent that these acidcompositions are considered much safer for handling on worksites.

SUMMARY OF THE INVENTION

Compositions according to the present invention have been developed forthe oil & gas industry and its associated applications, by targeting theproblems of metal corrosion, logistics/handling, human/environmentalexposure and formation/fluid compatibilities.

It is an object of the present invention to provide a synthetic acidcomposition which can be used over a broad range of applications in theoil and gas industry and which exhibit advantageous properties overknown compositions.

According to one aspect of the present invention, there is provided asynthetic acid composition which, upon proper use, results in a very lowcorrosion rate of oil and gas industry tubulars/equipment.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which isbiodegradable.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which has acontrolled spending (reacting) nature that is near linear as temperatureincreases, non-fuming, non-toxic, and has a highly controlledmanufacturing process ensuring consistent end product strength.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which has a pHbelow 1.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which hasminimal exothermic reactivity upon dilution or reaction. Typicallyadding a strong acid to a fluid (water, base etc.) will cause anaggressive rise in fluid temperature. Certain preferred embodiments ofthe present invention do not exhibit this effect to the same degree suchthat the exothermic reaction is minimal when combined with typicalindustrial fluids, such saline water, fresh water or even a high pHfluid.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which iscompatible with existing industry additives.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which has highsalinity tolerance. A tolerance for high salinity fluids, or brines, isdesirable for onshore and offshore acid applications. Conventional acidsare normally blended with fresh water and additives, typically faroffsite, and then transported to the area of treatment as a finishedblend. It is advantageous to have an alternative that can be transportedas a concentrate safely to the treatment area, then blended with asaline produced water or sea water greatly reducing the logisticsrequirement. A conventional acid system may precipitate salts/mineralsheavily if blended with fluids of an excessive saline level resulting information plugging or ancillary damage inhibiting production andsubstantially increasing costs. Brines are also typically present informations, thus having an acid system that has a high tolerance forbrines greatly reduces the potential for formation damage or emulsionsforming down-hole during or after product placement/spending occurs.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which isimmediately reactive upon contact/application. Many acids that areconsidered safe have a slower reaction rate, a reduced capacity tosolubilize, or a delayed reaction rate, making them ineffective oruneconomical in some applications. Strong mineral acids have very highhazards associated to them, but are immediately reactive. Preferredembodiments of the present invention are immediately active, even atlower concentrations. This immediate activity allows for a standardoperating procedure to be followed, minimizing operational changes. Manyoperations that utilize a mineral acid, such as HCl, will not need toalter their standard operating procedure to utilize preferredcompositions of the present invention.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which resultsin less unintended near wellbore erosion due to the controlled reactionrate. This, in turn, results in deeper formation penetration, increasedpermeability, and reduces the potential for zonal communication during atypical ‘open hole’ mechanical isolation application treatment. As ahighly reactive acid, such as hydrochloric acid, is deployed into a wellthat has open hole packers for isolation (without casing) there is apotential to cause a loss of neat-wellbore compressive strengthresulting in communication between zones or sections of interest as wellas potential sand production, and fines migration. It is advantageous tohave an alternative that will react with a much more controlled rate orspeed, thus greatly reducing the potential for zonal communication andthe above potential negative side effects of traditional acid systems.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry saidcomposition having a low evaporation rate. Acids normally utilized inindustrial operations typically have a high tendency to evaporate orfume, especially at higher concentrations. Preferred embodiments of thepresent invention do not exhibit this tendency and have very low fumingeffect, even in at high concentration. Hydrochloric acid will producehazardous fumes, such as chlorine gas, which can be fatal in higherconcentration. Preferred embodiments of the present invention do notproduce hazardous fumes, in any concentration.

According to another aspect of the present invention, there is provideda synthetic acid composition for use in the oil industry which providesa controlled and comprehensive reaction throughout a broad range oftemperatures. Preferred embodiments of the present invention havereaction rates that can be controlled or greatly “slowed or increased”for specific applications where a reduced (or increased) reaction rateis an advantage simply by adjusting the amount of water blended with theproduct. Preferred compositions of the present invention can be dilutedsubstantially <10%, yet still remain effective in many applications,such as scale control, as well as further increasing the HSE benefits.As preferred compositions of the present invention are diluted thereaction rate, or solubilizing ability, of the product will remainlinear.

Accordingly, the product would overcome many of the drawbacks found inthe use of compositions of the prior art related to the oil & gasindustry.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to stimulateformations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to assist inreducing breakdown pressures during downhole pumping operations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to treat wellborefilter cake post drilling operations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to assist in freeingstuck pipe.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to descale pipelinesand/or production wells.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to increase theinfectivity rate of injection wells.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to lower the pH offluids.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to removeundesirable scale in surface equipment, wells and related equipmentand/or facilities.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to fracture wells.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to perform matrixstimulations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to conduct annularand bullhead squeezes & soaks.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to pickle tubing,pipe and/or coiled tubing.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to increaseeffective permeability of formations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to reduce or removewellbore damage.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to cleanperforations.

According to an aspect of the present invention, there is provided a useof a synthetic acid composition in the oil industry to solubilizelimestone, dolomite, calcite and combinations thereof.

According to an aspect of the invention, there is provided a syntheticacid composition comprising:

-   -   urea & hydrogen chloride in a molar ratio of not less than        0.1:1; preferably in a molar ratio not less than 0.5:1, more        preferably in a molar ratio not less than 1.0:1;    -   a metal iodide or iodates, preferably cupric iodide, potassium        iodide, lithium iodide or sodium iodide; in an amount ranging        from 0.01-0.5%, preferably in an amount of approximately 0.022%;        potassium iodide is the preferred compound;    -   an alcohol or derivative thereof, preferably alkynyl alcohol,        more preferably a derivative of propargyl alcohol; in an amount        ranging from 0.1-2.0%, preferably in an amount of approximately        0.25%; 2-Propyn-1-ol, complexed with methyloxirane is the        preferred component;    -   optionally, formic acid or a derivative thereof selected from        the group consisting of: acetic acid, ethylformate and butyl        formate are present in an amount ranging from 0.05-2.0%,        preferably in an amount of approximately 0.1%; formic acid is        the preferred compound;    -   optionally, cinnamaldehyde or a derivative amine thereof;        present in an amount ranging from 0.01-1.0%, preferably in an        amount of approximately 0.03%; cinnamaldehyde is the preferred        compound;    -   optionally a propylene glycol or a derivative thereof present in        an amount ranging from 0.05-1.0%, preferably in an amount of        approximately 0.05%; propylene glycol is the preferred compound;        and    -   optionally, a phosphonic acid or derivatives, preferably        alkylphosphonie acid or derivatives thereof and more preferably        amino tris methylene phosphonic acid and derivatives thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The description that follows, and the embodiments described therein, isprovided by way of illustration of an example, or examples, ofparticular embodiments of the principles of the present invention. Theseexamples are provided for the purposes of explanation, and notlimitation, of those principles and of the invention.

Urea-HCl is the main component in terms of volume and weight percent ofthe composition of the present invention, and consists basically of acarbonyl group connecting with nitrogen and hydrogen. When added tohydrochloric acid, there is a reaction that results in ureahydrochloride, which basically traps the chloride ion within themolecular structure. This reaction greatly reduces the hazardous effectsof the hydrochloric acid on its own, such as the fuming effects, thehygroscopic effects, and the highly corrosive nature (the Cl⁻ ion willnot readily bond with the Fe ion). The excess nitrogen can also act as acorrosion inhibitor at higher temperatures. Urea & Hydrogen chloride ina molar ratio of not less than 0.1:1; preferably in a molar ratio notless than 0.5:1, and more preferably in a molar ratio not less than1.0:1. However, this ratio can be increased depending on theapplication.

It is preferable to add the urea at a molar ratio greater than 1 to themoles of HCl acid (or any acid). This is done in order to bind anyavailable CI′ ions, thereby creating a safer, more inhibited product.Preferably, the composition according to the present invention comprises1.05 moles of urea per 1.0 moles of HCl. The urea (hydrochloride) alsoallows for a reduced rate of reaction when in the presence ofcarbonate-based materials. This again due to the stronger molecularbonds associated over what hydrochloric acid traditionally displays.Further, since the composition according to the present invention ismainly comprised of urea (which is naturally biodegradable), the producttesting has shown that the urea hydrochloride will maintain the samebiodegradability function, something that hydrochloric acid will not onits own.

The use of formic acid as a corrosion inhibitor has been known fordecades. However, the high concentrations in which its use has beenreported along with the compounds it has been intermixed with have notmade it a desirable compound in many applications. Prior artcompositions containing formic acid require the presence of quinolinecontaining compounds or derivatives thereof, which render their use, inan increasingly environmentally conscious world, quite restricted.

In the present invention, formic acid or a derivative thereof such asformic acid, acetic acid, ethylformate and butyl formate can be added inan amount ranging from 0.05-2.0%, preferably in an amount ofapproximately 0.1%. Formic acid is the preferred compound, and isincluded on the PLONOR (Pose Little Or NO Risk to the environment) listfor offshore oilfield use.

Alcohols and derivatives thereof, such as alkyne alcohols andderivatives and preferably propargyl alcohol and derivatives thereof canbe used as corrosion inhibitors. Propargyl alcohol itself istraditionally used as a corrosion inhibitor which works extremely wellat low concentrations. It is however a very toxic/flammable chemical tohandle as a concentrate, so care must be taken when exposed to theconcentrate. In the composition according to the present invention, itis preferred to use 2-Propyn-1-ol, complexed with methyloxirane, as thisis a much safer derivative to handle. This is also a product that isapproved for use offshore in the North Sea oilfield areas.

Metal iodides or iodates such as potassium iodide, sodium iodide,cuprous iodide and lithium iodide can potentially be used as corrosioninhibitor intensifier. In fact, potassium iodide is a metal iodidetraditionally used as corrosion inhibitor intensifier, however it isexpensive, but works extremely well. It is non-regulated and friendly tohandle, and is included on the PLONOR (Pose Little Or NO Risk to theenvironment) list for offshore oilfield use.

Phosphonic acids and derivatives such as amino tris methylene phosphonicacid (ATMP) have some value as scale inhibitors. In fact, ATMP is achemical traditionally used as an oilfield scale inhibitor, it has beenfound, when used in combination with urea/HCl, to increase the corrosioninhibition or protection. It has a good environmental profile, isreadily available and reasonably priced.

Amino tris (methylenephosphonic acid) (ATMP) and its sodium salts aretypically used in water treatment operations as scale inhibitors. Theyalso find use as detergents and in cleaning applications, in paper,textile and photographic industries and in off-shore oil applications.Pure ATMP presents itself as a solid but it is generally obtainedthrough process steps leading to a solution ranging from beingcolourless to having a pale yellow colour. ATMP acid and some of itssodium salts may cause corrosion to metals and may cause serious eyeirritation to a varying degree dependent upon the pH/degree ofneutralization.

ATMP must be handled with care when in its pure form or not incombination with certain other products. Typically, ATMP present inproducts intended for industrial use must be maintained in appropriateconditions in order to limit the exposure at a safe level to ensurehuman health and environment.

Amino tris (methylenephosphonic acid) and its sodium salts belong to theATMP category in that all category members are various ionized forms ofthe acid. This category includes potassium and ammonium salts of thatacid. The properties of the members of a category are usuallyconsistent. Moreover, certain properties for a salt, in ecotoxicitystudies, for example, can be directly appreciated by analogy to theproperties of the parent acid. Amino tris (methylenephosphonic acid) mayspecifically be used as an intermediate for producing the phosphonatessalts. The salt is used in situ (usually the case) or stored separatelyfor further neutralization. One of the common uses of phosphonates is asscale inhibitors in the treatment of cooling and boiler water systems.In particular, for ATMP and its sodium salts are used in to prevent theformation of calcium carbonate scale.

In preferred embodiments of the present invention, 2-Propyn-1-ol,complexed with methyloxirane can be present in a range of 0.1-2.0%,preferably it is present in an amount of approximately 0.25%. PotassiumIodide can be present in a range of 0.01-0.5%, preferably it is presentin an amount of approximately 0.022%. Formic Acid can be present in arange of 0.05-2.0%, preferably it is present in an amount ofapproximately 0.1%.

As a substitute for traditional propargyl alcohol, a preferredembodiment of the present invention uses 2-Propyn-1-ol, complexed withmethyloxirane. As a substitute for potassium iodide one could use sodiumiodide, copper iodide and lithium iodide. However, potassium iodide isthe most preferred. As a substitute for formic acid one could use aceticacid. However, formic acid is most preferred. As a substitute forpropylene glycol one could use ethylene glycol, glycerol or a mixturethereof. Propylene glycol being the most preferred. As a substitute forcinnamaldehyde one could use cinnamaldehyde derivatives and aromaticaldehydes selected from the group consisting of dicinnamaldehydep-hydroxycinnamaldehyde; p-methylcinnamaldehyde; p-ethylcinnamaldehyde;p-methoxycinnamaldehyde; p-dimethylaminocinnamaldehyde;p-diethylaminocinnamaldehyde; p-nitrocinnamaldehyde;o-nitrocinnamaldehyde; 4-(3-propenal)cinnamaldehyde; p-sodiumsulfocinnamaldehyde n-trimethylammoniumcinnamaldehyde sulfate;p-trimethylammoniumcinnamaldehyde o-methylsulfate;p-thiocyanocinnamaldehyde; p-(S-acetyl)thiocinnamaldehyde;p-(S—N,N-dimethylcarbannoylthio)cinnamaldehyde; p-chorocinnamaldehyde;α-methylcinnamaldehyde; β-methylcinnamaldehyde; α-chlorocinnamaldehydeα-bromocinnamaldehyde; α-butylcinnamaldehyde; α-amylcinnamaldehyde;α-hexylcinnamaldehyde; α-bromo-p-cyanocinnamaldehyde;α-ethyl-p-methylcinnamaldehyde and p-methyl-α-pentylcinnamaldehyde. Themost preferred is cinnamaldehyde.

Example 1—Process to Prepare a Composition According to a PreferredEmbodiment of the Invention

Start with a 50% by weight solution of pure urea liquor. Add a 36% byweight solution of hydrogen chloride while circulating until allreactions have completely ceased. The ATMP is then added followed bypropargyl alcohol (or derivative), and potassium iodide. Circulation ismaintained until, all products have been solubilized. Additionalproducts are added now as required (iron control, demulsifier, etc.).

Table 1 lists the components of the composition of Example 1, includingtheir weight percentage as compared to the total weight of thecomposition and the CAS numbers of each component.

TABLE 1 Composition of a certain embodiment of the present inventionChemical % Wt Composition CAS# Water 60.315 7732-18-5 Urea Hydrochloride 39.0% 506-89-8 Amino tris methylene phosphonic acid 0.576% 6419-19-8Propargyl Alcohol 0.087% 107-19-7 Potassium Iodide 0.022% 7681-11-0

The resulting composition of Example 1 is a clear, odourless liquidhaving shelf-life of greater than 1 year. It has a freezing pointtemperature of approximately minus 30° C. and a boiling pointtemperature of approximately 1.00° C. It has a specific gravity of1.15±0.02. It is completely soluble in water and its pH is less than 1.

The composition is biodegradable and is classified as a non-irritantaccording to the classifications for skin tests. The composition isnon-fuming and has no volatile organic compounds nor does it have anyBTEX levels above the drinking water quality levels. BTEX refers to thechemicals benzene, toluene, ethylbenzene and xylene. Toxicity testingwas calculated using surrogate information and the LD₅₀ was determinedto be greater than 2000 mg/kg.

With respect to the corrosion impact of the composition on typicaloilfield grade steel, it was established that it was clearly well belowthe acceptable corrosion limits set by industry for certainapplications, such as spearhead applications or lower temperaturescaling.

Example 2

Table 2 lists the components of the composition of Example 2 includingtheir weight percentage as compared to the total weight of thecomposition and the CAS numbers of each component

TABLE 2 Composition according to an embodiment of the present inventionChemical % Wt Composition CAS# Water 58.92% 7732-18-5 Urea Hydrochloride 40.6% 506-89-8 2-Propyn-1-ol, complexed with  0.2% 38172-91-7methyloxirane Potassium Iodide  0.05% 7681-11-0 Formic Acid  0.15%64-18-6 Propylene Glycol  0.05% 57-55-6 Cinnamaldehyde  0.03% 14371-10-9Corrosion Testing

The composition of Example 2 according to the present invention wasexposed to corrosion testing. The results of the corrosion tests arereported in Table 3.

Samples of J55 grade steel were exposed to various synthetic acidsolutions for periods of time ranging up to 24 hours at 90° C.temperatures. All of the tested compositions contained HCl and urea in a1:1.05 ratio,

TABLE 3 Corrosion testing comparison between HCl-Urea and thecomposition of Example 2 at a 100% concentration Initial Final LossSurface Run Inhibitor wt. wt. wt. area Density time (%) (g) (g) (g)(cm2) (g/cc) (hours) Mils/yr mm/year lb/ft² HCl-Urea 37.616 34.324 3.09228.922 7.86 6 7818.20 198.582 0.222 HCl-Urea 37.616 31.066 6.550 28.9227.86 24 4140.46 105.168 0.470 Example #2 37.524 37.313 0.211 28.922 7.866 533.519 13.551 0.015 Example #2 37.524 35.540 1.984 28.922 7.86 241254.149 31.855 0.142

This type of corrosion testing helps to determine the impact of the useof such synthetic replacement acid composition according to the presentinvention compared to the industry standard HCl blends or any othermineral or organic acid blends). The results obtained for thecomposition containing only HCl and urea were used as a baseline tocompare the other compositions.

Additionally, the compositions according to the present invention willallow the end user to utilize an alternative to conventional acids thathas transportation and storage advantages as well as health, safety andenvironmental advantages. Enhancement in short/long term corrosioncontrol is one of the key advantages of the present invention. Thereduction in skin corrosiveness, the elimination of corrosive fumes, thecontrolled spending nature, and the high salt tolerance are some otheradvantages of compositions according to the present invention.

Aquatic Toxicity Testing

The biological test method that was employed was the Reference Methodfor Determining acute lethality using rainbow trout (1990—EnvironmentCanada, EPS 1/RM/9—with the May 1996 and May 2007 amendments).

The Trout 96 hour Acute Test (WTR-ME-041) was performed at 5 differentconcentrations of compositions (62.5, 125, 250, 500 and 1000 ppm) onereplicate per treatment, ten fish per replicate.

The test results indicate that at concentrations of the composition ofExample 2 of up to and including 500 ppm there was a 100% survival ratein the fish sample studied. This is an indicator that the composition ofExample 2 demonstrates an acceptable environmental safety profile.

Dermal Testing

The objective of this study was to evaluate the dermal irritancy andcorrosiveness of the composition of Example 2, following a singleapplication to the skin of New Zealand White rabbits. The undiluted testsubstance was placed on the shaved back of each of the three rabbitsused in the study. The treated site was then covered by a gauze patchand secured with porous tape. The entire midsection of each rabbit waswrapped in lint-free cloth secured by an elastic adhesive bandage. Theuntreated skin site of each rabbit served as a control for comparisonpurposes. All wrapping materials were removed from each rabbit 4 hoursfollowing application of the test substance. The application site wasthen rinsed with water and wiped with gauze to remove any residual testsubstance. The skin of each rabbit was examined at 30-GO minutes and 24,48 and 72 hours following removal of the wrappings. Descriptions of skinreactions were recorded for each animal. Dermal irritation scores werecalculated for each time point, and a Primary Dermal Irritation Scorewas calculated according to the Draize descriptive ratings for skinirritancy.

Tables 4 and 5 report the results of the dermal testing. The scores foredema and erythema/eschar formation were “0” at all scoring intervalsfor all three rabbits. According to the Draize descriptive ratings forskin irritancy, the Primary Dermal Irritation Score (based on the 24-and 72-hour scoring intervals) for the test substance under theconditions employed in this study was 0.00. Thus, the composition ofExample 2 was determined to be a non-irritant to the skin of New ZealandWhite rabbits. However, this conclusion was drawn withoutcharacterization of the test substance.

TABLE 4 Description of Individual Skin Reactions upon exposure tocomposition of Example 2 Scoring Interval (Time Following Removal ofWrappings) Animal 30-60 24 48 72 Number Minutes Hours Hours Hours (sex)Skin Reactions Scores 819 (F) Edema^(b) 0 0 0 0 Erythema/eschar^(c) 0 00 0 820 (F) Edema 0 0 0 0 Erythema/eschar 0 0 0 0 821 (F) Edema 0 0 0 0Erythema/eschar 0 0 0 0 ^(a)see protocol Table 1 (Appendix A) for adetailed description of the Draize scoring scale (Draize, J. H.,Appraisal of the Safety of Chemicals in Foods, Drugs, and Cosmetics,Assoc. Food & Drug Officials of the U.S., Austin, TX, 1959) ^(b)edema: 0= none, 1 = very slight, 2 = slight, 3 = moderate, 4 (maximum possible)= severe ^(c)erythema/eschar: 0 = none, 1 = very slight, 2 =well-defined, 3 = moderate to severe, 4 (maximum possible) = severeerythema to slight eschar formation

TABLE 5 Primary Dermal Irritation Score of Individual Skin Reactionsupon exposure to composition of Example 2 Scoring Interval (TimeFollowing Removal of Wrappings) 30-60 30-60 30-60 30-60 Minutes MinutesMinutes Minutes Edema Score Skin Reactions Scores Summary^(b) 0 3/3 3/33/3 3/3 1 0/3 0/3 0/3 0/3 2 0/3 0/3 0/3 0/3 3 0/3 0/3 0/3 0/3 4 0/3 0/30/3 0/3 Positive Score Mean 0.00 0.00 0.00 0.00 Erythema and/or EscharFormation Score Skin Reactions Scores Summary^(b) 0 3/3 3/3 3/3 3/3 10/3 0/3 0/3 0/3 2 0/3 0/3 0/3 0/3 3 0/3 0/3 0/3 0/3 4 0/3 0/3 0/3 0/3Positive Score Mean 0.00 0.00 0.00 0.00 Irritation Score 0.00 0.00 0.000.00 Subtotal^(c) PRIMARY DERMAL 0.00 (24-hour subtotal) + 0.00 (72-hoursubtotal) = 0.00 (total score) IRRITATION 0.00 (total score)/2 = 0.00(Primary Dermal Irritation Score) SCORE (DRAIZE): ^(a)see protocol Table1 (Appendix A) for a detailed description of the Draize scoring scale(Draize, J. H., Appraisal of the Safety of Chemicals in Foods, Drugs,and Cosmetics, Assoc. Food & Drug Officials of the U.S., Austin, TX,1959) ^(b)Number or animals with score/number of animals dosed^(c)Irritation score subtotal = mean erythema score + mean edema scoreCorrosion Testing

Corrosion testing using the composition of Example 2 was carried outunder various conditions of temperature and on different steels to showthe breadth of the applications for which compositions according to thepresent invention can be used. Table 6 sets out the test results ofcorrosion test that were carried out on N-80 steel (density of 7.86g/ee) using the composition of Example 2 at a 50% concentration. Table 7reports the test results of corrosion tests that were carried out onJ-55 steel (density of 7.86 g/cc) using the composition of Example 2 ata 50% concentration. Table 8 reports the test results of corrosion teststhat were carried out on various metal samples using the composition ofExample 2 at a 100% concentration. These test results show that thecomposition of Example 2 meets the regulatory standards for thetransportation industry on mild steel, and provides a strong level ofprotection with respect to aluminum.

TABLE 6 Corrosion tests carried out on N-80 steel (density of 7.86 g/cc)using the composition of Example 2 at a 50% concentration Initial FinalLoss Surface Run Temp Wt. wt. wt. Area Time ° C. (g) (g) (g) (cm2)(hours) Mils/yr mm/year lb/ft2 70° C. 40.898 40.863 0.035 27.11 694.41353 2.398 0.003 70° C. 40.898 40.816 0.082 27.11 24 55.29936 1.4050.006 90° C. 40.896 40.838 0.058 27.11 6 156.4567 3.974 0.004 90° C.40.896 40.740 0.156 27.11 24 105.2037 2.672 0.011

TABLE 7 Corrosion tests carried out on J-55 steel (density of 7.86 g/cc)using the composition of Example 2 at a 50% concentration Initial FinalLoss Surface Run Temp Wt. wt. wt. Area Time ° C. (g) (g) (g) (cm2)(hours) Mils/yr mm/year lb/ft2 30° C. 37.705 37.700 0.005 28.922 612.64263 0.321 0.000 30° C. 37.705 37.692 0.013 28.922 24 8.217709 0.2090.001 30° C. 37.705 37.676 0.029 28.922 72 6.110604 0.155 0.002 50° C.37.513 37.502 0.011 28.922 6 27.81378 0.706 0.001 50° C. 37.513 37.4850.028 28.922 24 17.69968 0.450 0.002 70° C. 37.435 37.396 0.039 28.922 698.61251 2.505 0.003 70° C. 37.435 37.350 0.085 28.922 24 53.73117 1.3650.006 90° C. 37.514 37.430 0.084 28.922 6 212.3962 5.395 0.006 90° C.37.514 37.255 0.259 28.922 24 163.7221 4.159 0.018

TABLE 8 Corrosion tests carried out on various metal samples using thecomposition of Example 2 at a 100% concentration Initial Final LossSurface Run Temp Wt. wt. wt. Area Density Time Coupon ° C. (g) (g) (g)(cm2) g/cc (hours) Mils/yr mm/year lb/ft2 1018 steel 55° C. 13.99413.955 0.039 28.503 7.82 72 8.381163 0.213 0.003 7075 25° C. 6.196 6.1850.011 29.471 2.81 6 76.35013 1.939 0.001 aluminum 7075 25° C. 6.1966.080 0.116 29.471 2.81 24 201.2867 5.113 0.008 aluminum 7075 25° C.6.196 1.344 4.852 29.471 2.81 48 4209.668 106.926 0.344 aluminum

Example 3

Table 9 lists the components of the composition of Example 3 includingtheir weight percentage as compared to the total weight of thecomposition and the CAS numbers of each component.

TABLE 9 Composition of a preferred embodiment of the present inventionChemical % Wt Composition CAS# Water 59.028% 7732-18-5 UreaHydrochloride  40.6% 506-89-8 2-Propyn-1-ol, complexed with  0.25%38172-91-7 methyloxirane Potassium Iodide  0.022% 7681-11-0 Formic Acid  0.1% 64-18-6Corrosion Testing

The compositions of Example 2 and 3 according to the present inventionwere exposed to corrosion testing. The results of the corrosion testsare reported in Table 10.

Samples of J55 grade steel were exposed to various synthetic acidsolutions for periods of time ranging up to 24 hours at 90° C.temperatures. All of the tested compositions contained HCl and urea in a1:1.05 ratio.

TABLE 10 Corrosion testing comparison between HCl-Urea and thecompositions of Example 2 and 3 at a 100% concentration Initial FinalLoss Surface Run Inhibitor wt. wt. wt. area Density time (%) (g) (g) (g)(cm2) (g/cc) (hours) Mils/yr mm/year lb/ft² HCl-Urea 37.616 34.524 3.09228.922 7.86 6 7818.20 198.582 0.222 HCl-Urea 37.616 31.066 6.550 28.9227.86 24 4140.46 105.168 0.470 Example #2 37.524 37.313 0.211 28.922 7.866 533.519 13.551 0.015 Example #2 37.524 35.540 1.984 28.922 7.86 241254.149 31.855 0.142 Example #3 37.714 37.520 0.194 28.922 7.86 6490.534 12.460 0.014 Example #3 37.714 37.329 0.385 28.922 7.86 24243.371 6.182 0.027

This type of corrosion testing helps to determine the impact of the useof such synthetic replacement acid composition according to the presentinvention compared to the industry standard (MCI blends or any othermineral or organic acid blends). The results obtained for thecomposition containing only HCl and urea were used as a baseline tocompare the other compositions. Additionally, the compositions accordingto the present invention will allow the end user to utilize analternative to conventional acids that has the down-hole performanceadvantages, transportation and storage advantages as well as the health,safety and environmental advantages. Enhancement in short/long termcorrosion control is one of the key advantages of the present invention.The reduction in skin corrosiveness, the elimination of corrosive fumes,the controlled spending nature, and the high salt tolerance are someother advantages of compositions according to the present invention.

Aquatic Toxicity Testing

The biological test method that was employed was the Reference Methodfor Determining acute lethality using rainbow trout (1990—EnvironmentCanada, EPS 1/RM/9—with the May 1996 and May 2007 amendments).

The Trout 96 hour Acute Test (WTR-ME-041) was performed at 5 differentconcentrations of compositions (62.5, 125, 250, 500 and 1000 ppm) onereplicate per treatment, ten fish per replicate.

The test results indicate that at concentrations of the composition ofExample 3 of up to and including 500 ppm there was a 100% survival ratein the fish sample studied. This is an indicator that the composition ofExample 3 demonstrates a highly acceptable environmental safety profile.

Additional testing was carried out to assess the inhibition of marinealgal growth, acute toxicity and biodegradability establish the safetyfor the environment.

Elastomer Testing

When common sealing elements used in the oil and gas industry come incontact with acid compositions they tend to degrade or at least showsign of damage. A number of sealing elements common to the industry wereexposed to a composition according to a preferred embodiment of thepresent invention to evaluate the impact of the latter on theirintegrity. More specifically, the hardening and drying and the loss ofmechanical integrity of sealing elements can have substantialconsequences to the operations of wells and result in undesirable shutdowns to replace defective sealing elements. Testing was carried out toassess the impact of the exposure of composition of Example 3 to variouselastomers. Long term (72 hour exposure) elastomer testing on theconcentrated product of Example 3 at 70° C. and 28,000 kPa showed littleto no degradation of various elastomers, including Nitrile 70, Viton 75,Atlas 80, and EPDM 70 style sealing elements.

Corrosion Testing

Corrosion testing using the composition of Example 3 was carried outunder various conditions of temperature and on different steels to showthe breadth of the applications for which compositions according to thepresent invention can be used. Table 11 sets out the test results ofcorrosion test that were carried out on N-80 steel (density of 7.86g/cc) using the composition of Example 3 at a 50% concentration. Table12 reports the test results of corrosion tests that were carried out onJ-55 steel (density of 7.86 Wee) using the composition of Example 3 at a50% concentration. Table 13 reports the test results of corrosion teststhat were carried out on various metal samples using the composition ofExample 3 at a 100% concentration. These test results show that thecomposition of Example 3 meets the regulatory standards for thetransportation industry on mild steel, and provide a strong level ofprotection with respect to aluminum. Table 14 lists a number ofapplications for which compositions according to the present inventioncan be used as well as proposed dilution ranges.

TABLE 11 Corrosion tests carried out on N-80 steel (density of 7.86g/cc) using the composition of Example 3 at a 50% concentration InitialFinal Loss Surface Run Temp Wt. wt. wt. Area Density Time ° C. (g) (g)(g) (cm2) g/cc (hours) Mils/yr mm/year lb/ft2 70° C. 40.757 40.708 0.04927.11 7.86 6 132.1789 3.357 0.003 70° C. 40.757 40.609 0.148 27.11 7.8624 99.80859 2.535 0.010 90° C. 40.712 40.617 0.095 27.11 7.86 6 256.26536.509 0.007 90° C. 40.712 40.475 0.237 27.11 7.86 24 159.8286 4.0600.017

TABLE 12 Corrosion tests carried out on J-55 steel (density of 7.86g/cc) using the composition of Example 3 at a 50% concentration InitialFinal Loss Surface Run Temp Wt. wt. wt. Area Density Time ° C. (g) (g)(g) (cm2) g/cc (hours) Mils/yr mm/year lb/ft2 50° C. 38.366 38.342 0.02428.922 7.86 6 60.68462 1.541 0.002 50° C. 38.366 38.323 0.043 28.9227.86 24 27.18165 0.690 0.003 70° C. 38.728 38.596 0.132 28.922 7.86 6333.7654 8.478 0.009 70° C. 38.728 38.448 0.280 28.922 7.86 24 176.99684.496 0.020 90° C. 37.543 37.463 0.080 28.922 7.86 6 202.2821 5.1380.006 90° C. 37.543 37.106 0.437 28.922 7.86 24 276.2415 7.017 0.031

TABLE 13 Corrosion tests carried out on various metal samples using thecomposition of Example 3 at a 100% concentration Initial Final LossSurface Run Temp Wt. wt. wt. Area Density Time Coupon ° C. (g) (g) (g)(cm2) g/cc (hours) Mils/yr mm/year lb/ft2 1018 steel 55° C. 13.99413.955 0.039 28.503 7.82 72 8.381163 0.213 0.003 7075 25° C. 6.196 6.0800.116 29.471 2.81 24 201.2867 5.113 0.008 aluminum 7075 25° C. 6.1961.344 4.852 29.471 2.81 48 4209.668 106.926 0.344 aluminum

The uses (or applications) of the compositions according to the presentinvention upon dilution thereof ranging from approximately 1 to 75%dilution, include, but are not limited to: injection/disposaltreatments; matrix acid squeezes, soaks or bullheads; acid fracturing,acid washes; fracturing spearheads (breakdowns); pipeline scaletreatments, cement breakdowns or perforation cleaning; pH control; andde-scaling applications.

TABLE 14 Applications for which compositions according to the presentinvention can be used as well as proposed dilution ranges Application:Suggested Dilution: Benefits: Injection/Disposal 50% Compatible withmutual solvents and solvent Wells blends, very cost effective. Squeezes& Soaks 33%-50% Ease of storage & handling, cost effective Bullheadcompared to conventional acid stimulations. Annular Ability to leavepump equipment in wellbore. Acid Fracs 50%-75% Decreased shipping andstorage compared to conventional acid, no blend separation issues,comprehensive spend rate encourages deeper formation penetration. FracSpearheads 33%-66% Able to adjust concentrations on the fly.(Break-downs) Decreased shipping and storage on location. CementBreak-downs 50% Higher concentrations recommended due to lowertemperatures, and reduced solubility of aged cement. pH Control0.1%-1.0% Used in a variety of applications to adjust pH level of waterbased systems. Liner De-Scaling, 1%-5% Continuous injection/de-scalingof slotted Heavy Oil liners, typically at very high temperatures.Use of a Composition According to the Present Spearhead on Multi-WellPad

An operator in Western Canada was performing horizontal multi-stagefracturing completions on a multiple well pad, using plug and perforatetechnology. Traditional methods of formation breakdown required the useof 6-10 m³ of 15% HCl acid to be pumped down the casing prior to eachfracturing stage.

Prior to testing, multiple samples of the high salinity fracturing water(recycled fracturing fluid) were tested for compatibility, as this wasproposed to be used as the diluents for the concentrated synthetic acid.By storing the concentrated synthetic acid composition in a tank anddiluting it with the fracturing water on site, only two storage tankswere required for the treatments (±360 m³ of spearhead acid). These areintended on being refilled periodically.

For each treatment, the tank of concentrated synthetic acid compositionwas blended on site through the fracturing blender with the fracturingwater down to reach a concentration of ±33% of the initial composition.6-10 in³ of the synthetic acid composition was pumped for each spearheadstage, all other operational components and procedures remained the sameas traditional methods using HCl acid (15% HCl acid was on location fora comparison well).

A total of 18 stages per well were treated on more than 8 wells, with100% breakdown success on every stage. Breakdown pressure differentialsin the range of 10-15 MPa were observed, and were found to be verycomparable to HCl acid.

The main advantages of the use of the synthetic acid compositionincluded: the reduction of the total loads of acid, and the requirednumber of tanks by delivering concentrated product to location anddiluting with fluids available on location (high salinity productionwater). Other advantages of the composition according to the presentinvention include: operational efficiencies which led to the eliminationof having to periodically circulate tanks of HCl acid due to chemicalseparation; reduced potential corrosion to downhole tuhulars; andreduced HCl acid exposure to personnel by having a non-hazardous,non-fuming acid on location.

While the foregoing invention has been described in some detail forpurposes of clarity and understanding, it will be appreciated by thoseskilled in the relevant arts, once they have been made familiar withthis disclosure, that various changes in form and detail can be madewithout departing from the true scope of the invention in the appendedclaims.

What is claimed is:
 1. A synthetic acid composition for use in oilindustry activities, said composition comprising: urea and hydrogenchloride in a molar ratio of not less than 0.1:1; a metal iodide oriodate; an alcohol or derivative thereof; and wherein the use in the oilindustry is to stimulate formations.
 2. The synthetic acid compositionaccording to claim 1, further comprising formic acid or derivativethereof.
 3. The synthetic acid composition according to claim 2, whereinthe formic acid or a derivative thereof is selected from the groupconsisting of: formic acid, acetic acid, ethyl formate and butylformate.
 4. The synthetic acid composition according to claim 3, wherethe formic acid or derivative thereof is present in an amount rangingfrom 0.05-2.0% by weight of the composition.
 5. The synthetic acidcomposition according to claim 2, where the formic acid or derivativethereof is formic acid.
 6. The synthetic acid composition according toclaim 1, further comprising propylene glycol or derivative thereof,ethylene glycol, glycerol or a mixture thereof.
 7. The synthetic acidcomposition according to claim 6, where the compound selected from thegroup consisting of: propylene glycol or derivative thereof, ethyleneglycol, glycerol or a mixture thereof, is present in a range of0.05-1.0% by weight of the composition.
 8. The synthetic acidcomposition according to claim 1, further comprising cinnamaldehyde or aderivative thereof.
 9. The synthetic acid composition according to claim8 where cinnamaldehyde or derivative thereof is present in the range of0.01-1.0% by weight of the composition.
 10. The synthetic acidcomposition according to claim 1, wherein the urea and hydrogen chlorideare in a molar ratio of not less than 0.5:1.
 11. The synthetic acidcomposition according to claim 10, wherein the urea and hydrogenchloride are in a molar ratio of not less than 1.0:1.
 12. The syntheticacid composition according to claim 1, wherein the phosphonic acidderivative is aminoalkylphosphonic salt.
 13. The synthetic acidcomposition according to claim 12, wherein the aminoalkylphosphonic saltis amino tris methylene phosphonic acid.
 14. The synthetic acidcomposition according to claim 12, wherein the aminoalkylphosphonic saltis present in a concentration ranging from 0.25 to 1.0% w/w.
 15. Thesynthetic acid composition according to claim 1, wherein the metaliodide or iodate is cuprous iodide.
 16. The synthetic acid compositionaccording to claim 1, wherein the metal iodide or iodate is potassiumiodide.
 17. The synthetic acid composition according to claim 1, whereinthe metal iodide or iodate is sodium iodide.
 18. The synthetic acidcomposition according to claim 1, wherein the metal iodide or iodate islithium iodide.
 19. The synthetic acid composition according to claim 1,wherein the alcohol or derivative thereof is an alkynyl alcohol orderivative thereof.
 20. The synthetic acid composition according toclaim 19, wherein the alkynyl alcohol or derivative thereof is propargyl alcohol or a derivative thereof.
 21. The synthetic acidcomposition according to claim 19, wherein the alkynyl alcohol orderivative thereof is present in a concentration ranging from 0.1 to2.0% w/w.
 22. The synthetic acid composition according to claim 21,wherein the alkynyl alcohol or derivative thereof is present in aconcentration of 0.25% w/w.
 23. The synthetic acid composition accordingto claim 1, wherein the metal iodide is present in a concentrationranging from 100 to 500 ppm.
 24. The use of a synthetic acid compositionaccording to claim 1 in the oil industry to reduce or remove wellboredamage.
 25. The synthetic acid composition according to claim 1, furthercomprising a phosphonic acid derivative.
 26. A synthetic acidcomposition for use in oil industry activities, said compositioncomprising: urea and hydrogen chloride in a molar ratio of not less than0.1:1; a metal iodide or iodate; an alcohol or derivative thereof; andwherein the use in the oil industry is to treat wellbore filter cakepost drilling operations.
 27. A synthetic acid composition for use inoil industry activities, said composition comprising: urea and hydrogenchloride in a molar ratio of not less than 0.1:1; a metal iodide oriodate; an alcohol or derivative thereof; and wherein the use in the oilindustry is to descale pipelines and/or production wells.
 28. Asynthetic acid composition for use in oil industry activities, saidcomposition comprising: urea and hydrogen chloride in a molar ratio ofnot less than 0.1:1; a metal iodide or iodate; an alcohol or derivativethereof; and wherein the use in the oil industry is to increase aninjectivity rate of injection wells.
 29. A synthetic acid compositionfor use in oil industry activities, said composition comprising: ureaand hydrogen chloride in a molar ratio of not less than 0.1:1; a metaliodide or iodate; an alcohol or derivative thereof; and wherein the usein the oil industry is to lower the pH of fluids.
 30. A synthetic acidcomposition for use in oil industry activities, said compositioncomprising: urea and hydrogen chloride in a molar ratio of not less than0.1:1; a metal iodide or iodate; an alcohol or derivative thereof; andwherein the use in the oil industry is to remove undesirable scale insurface equipment, wells and related equipment and/or facilities.
 31. Asynthetic acid composition for use in oil industry activities, saidcomposition comprising: urea and hydrogen chloride in a molar ratio ofnot less than 0.1:1; a metal iodide or iodate; an alcohol or derivativethereof; and wherein the use in the oil industry is to fracture wells.32. A synthetic acid composition for use in oil industry activities,said composition comprising: urea and hydrogen chloride in a molar ratioof not less than 0.1:1; a metal iodide or iodate; an alcohol orderivative thereof; and wherein the use in the oil industry is toperform matrix stimulations.
 33. A synthetic acid composition for use inoil industry activities, said composition comprising: urea and hydrogenchloride in a molar ratio of not less than 0.1:1; a metal iodide oriodate; an alcohol or derivative thereof; and wherein the use in the oilindustry is to conduct annular and bullhead squeezes and soaks.
 34. Asynthetic acid composition for use in oil industry activities, saidcomposition comprising: urea and hydrogen chloride in a molar ratio ofnot less than 0.1:1; a metal iodide or iodate; an alcohol or derivativethereof; and wherein the use in the oil industry is to pickle tubing,pipe and/or coiled tubing.
 35. A synthetic acid composition for use inoil industry activities, said composition comprising: urea and hydrogenchloride in a molar ratio of not less than 0.1:1; a metal iodide oriodate; an alcohol or derivative thereof; and wherein the use in the oilindustry is to solubilize limestone, dolomite, calcite and combinationsthereof.